Question

how do the semicircular canals help maintain balance?
by amplifying sound waves to the brain.
by detecting movement of fluid that bends hair cells when the heads position changes.
by responding to chemicals that indicate motion.
by detecting light and sending signals about body position.

Explanation:

The semicircular canals are part of the vestibular system in the inner ear. They contain fluid that moves when the head changes position, bending hair cells within the canals; this triggers signals to the brain about balance and head movement. The other options are incorrect: amplifying sound waves is the role of the middle ear, responding to chemicals relates to taste/smell, and detecting light is the function of the eyes.

Answer:

By detecting movement of fluid that bends hair cells when the head's position changes.